Vacuum tank



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'WILFRED O. CHASE, 0F BEDFORD, ICCHIGAN, .SSIGNOR T0 STEVJART-WARNER SPEEDOMETER CBFORATON, OF GHIGAG, LLNIS, A CDRFRATION 0F VIR- GINIA.

VACUUM TANK.

Apploatcn filed October 2, 1922.

To all 107mm it may concern:

Be it known that I, VVILFRED O. CHASE, a citizen of the United States of America. residing at Redford, in the county of `Wayne and State of Michigan, have invented certain new and useful Improvements in Vac? uum Tanks, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to vacuum tanks more particularly designed for the supply of liquid fuel to internal combustion engines, and of thatl type in which the actuation and control of the movable parts is pneumatic. It is the object of the invention to obtain a construction which is more positive in its operation than constructions heretofore used and which is also free from certain defects of such prior constructions. To this end the invention consists in vvarious features as hereinafter set forth.

ln the drawings: n

Figure l is a vertical central section through a vacuum tank of my improved construction Figure 2 is a similar view showing the parts in different positions of adjustment;

Figure 3 is a perspective view of the shield for the iioat detached;

Figure l is a section through the fuel inlet screen.

ln general construction my improved tank comprises the casing A which is divided by a partition B into upper and lower compartments C and D. The upper compartment is closed by a head E, which has preferably formed therein the various ports, chambers and passages for the pneumatic control mechanism and the fluid supply.

In detail, the head E is provided with the vacuum connection F communicating with a laterally extending passage G with upwardly and downwardly extending aligned ports G and G2. H and H are valves for respectively closing said ports, the former being arranged to seat by gravity and the latter being mounted on the stem l of the float J located in the upper chamber C. The stem I loosely tits a guide bearing l at its upper end and at its lower end beneath the float is preferably Vprovided with a guide spider I2 engaging'a tubular fitting K forming theoutlet from the upper to the lower chamber.-

Tliis outlet is nor-` Serial No. 591,930.

mally opened, but is provided with the upwardly seating gravity released valve L, this being preferably of inverter4 cup-shape so as to be actuated in seating by an upward current of either air or liquid. Below the valve L is a contracted neck or nozzle L for discharging the l`quid stream in unbroken column.

The valve H has extending above the portion which engages the valve seat a tapering portion H2 which variably restricts the area of the port forming a. metering dcvice. H3 is a lateral port extending through the guide bearing li', which is so arranged is to be closed or greatly restricted when the valve is adjacent to its seat, but fully opened in the lowered position of said valve and float K. The valve H is mechanically unseated upon the seating of the valve H by the upward extension H2 and, on the other hand, the valve H is held from seating by the valve H when the latter is seated. rlhus to shift or reverse the valves H and H, ach must overcome the resist-ance of the other as will be hereinafter set forth.

rllhe port G', when opened by the unseating of the valve H, communica" vith a passage M connecting with a vertically arranged cylindrical passage N containing a gravity seating valve C for controlling a port (lt communicating with the upper chaniber C. Extending laterally from this chamiicr N is an atmospheric connecting passage l), the arrai'igement being such that the lifting` of the valve O by suction when the valve H is unseated will open the port C and vent the upper chamber C to atmosphere.

With the construction as thus far described, in the initial position of parts the valve L is unseated, leaving an open passage between the upper and lower compartments C and D. rlhe float J is in its lower position, which unseats the valve H and opens the port H3, establishing communication between the same and the port G2. The latter, in the unseated position of the valve H, is in free communication between the vacuum connection F, so that whenever suction occurs, it is communicated through said ports to the chamber C, causing an upward current (first of air) through the fitting K impinging on the inverted cup-shaped valve L. This will lift said valve to its seat,

thereby stopping further upward flow and creating a vacuum in the upper chamber. This chamber is connected with a supply tank through a conduit Q and therefore the liquid fuel will be drawn into said chamber and will exert an upward pressure upon the float J, causing it to rse until the tapering portion H2 of the stem comes in contact with the valve H. This will restrict the vacuum connection between the conduit F and the chamber C, bot-h by reason of the restriction in the area of the port G2 and the obstruction of the port H3. Further rise of the float is temporarily resisted by the valve H, which is held to its seat by atmospheric lpressure as opposed to the vacuum on its lower side. Consequently, the parts remain stationary until the hydrostatic pressure on the float is sufficient to overcome this resistance, whereupon the valve H is unseated and the valve H engages its seat. The unseating of the valve H communicates the vacuum to the cylindrical chamber N, lifting the valve 0 and opening the port O', which admits atmospheric pressure to the chamber C. This permits the valve L to drop by gravity and the liquid in the upper chamber to discharge through the open fitting K and noz- Zle L. From the lower chamber the liquid is discharged through a conduit R leading to the carburetor or otherY device to be supplied by fuel.

To permit discharge from the lower chainber during the filling of the upper chamber and the consequent closing of the valve L, an additional vent or atmospheric connection to said lower chamber is required. This may be formed by a tube S extending from the passage P downward through the partition B, but where such tube is open at all times, there is danger of a discharge of l'quid therethrough from the lower tank. Such discharge may be occasioned by pressure of expansion in the upper chamber when there is no suction upon the system and the valves H and O are both closed.

Thus increased pressure in such chamber will force liquid downward into the lower chamber and upward through the tube S to the atmospheric connection l?. The-pressure inthe upper chamber cannot exceed that required for unseating the valve O, but in practice it is found that to insure the proper seating of said valve O, it must be of sulicient weight to develop aV pressure more than equa-l to the hydrostatic column in the tube S. n

To overcome the difliculty just described, I have provided a valve for closing the tube S, which is automatically opened whenever there is suction in the upper chamber C, but will close when there is either atmospheric pressure or more than atmospheric pressure in said chamber. This construction comprises a fitting S connected to a return-bent portion of the tube S and passing through the partition B. Tn this fitting is a valve S2 having upper and lower seats S2 and S1 with lateral inlet ports therebetween and arranged below the partition B. The valve S2, which is preferably a ball, when resting on its lower seat, closes the tube S but opens communication'between the upper chamber C and the lower chamber D. On the other hand, when there is suction in the upper chamber C, the valve S2 will be lifted to its upper seat, cutting oil communication between the upper and lower chambers and opening communication between the tube t3 and the lower chamber. This will permit the discharge of liquid from the lower chainber so that the tank can properly function when the valve L is closed.

The lquid, which is drawn into the upper chamber C through the conduit Q, may interfere with the operation of the float either by direct impact thereon or by causing agitation in the body of liquid in the chamber. To guard against such a result, l have provided a` shield T which surrounds the lioat with suiiicientclearance to provide for lree movement thereof and which guards said float from impact of the incoming fluid. iis shown, this shield T is of slightly conical or tapering form, being provided at its upper end with a flange T clamped between the head or cover E and the body A of the, tank. At one side the shield in its upper portion is radially inwardly depressed to form a groove or channel T2 to which the, conduit Q connects. A strainer Q is also arranged in this channel, being iianged at its upper end and supported upon the flange T. Thus the incoming liquid will discharge from the channel T2 out of line with the float and will have no influence in disturbing said float.

l'n the complete operation the valves 1T and H are alterna-tively seated and unseat-- ed by the combined action ol pneumatic. hydrostatie and gravity pressures. lbenever there is suction in the connection F. this will assist in holding either the valve H or the valve H to its seat and will therefore teinporarily resist the opening of said valves by other forces, gravity or hydrostatic. Therefore, a fluttering of the valves, due to slight changes in pressure conditions, is avoided. The valve L being normally open and automatically opening` by gravity will permit the. free flow of iiuid from the upper to the lower chambers. The velocity of discharge is variable.v being` greatest when there is the least `fluid in the lower chamber and lessening as the lower chamber is filled with iiuid. Such variable discharge is eiiected by the discharge nozzle L. which tends to hold the discharging liquid in an unbroken column. Therefore, the hydrostatic pressure of such column is added to the force discharging from the liquid and will lc onsequently increase the velocity when the column is longest.

`When the valve H is closed and the valve l-l opened, the suction operating upon the valve O will li'l't the same to an upper seat O2, this cutting oif the suction connection to the atmospheric connecting passage l). The sealing ot the valve l) on the seat O2 not, however, complete so that whenever the valve ll is closed, the pressures below and above the valve (l will equalize, permitting the latter to :tall by gravity. Thus, in operation, the chamber C will be alternately lilled and discharged and at all times free 'feeding ot the liquid trom the lower chamber l) is permitted.

`What l claim as my invention is:

l. A vacuum tank comprising an upper compartment, suction means tor iilling the same, a lower compartment, a valve-controlled passage between said compartments, and means operated by suction in the upper compartment tor opening an atmospheric vent to said lower compartment.

2. A. vacuum tank comprising an upper compartnient, suction means for Filling the same, a lower compartment, a downwardly opening check valve controlling a passage between said compartments, an atmospheric vent tor said lower compartment, a check valve for closing the same against internal pressure, and means operated by suction in the upper compartment for opening said check valve.

3. A vacuum tank comprising a casing having an upper and lower compartment, suction operated means for illing the upper compartment, a downwardly opening check valve controlling the passage between said upper and lower compartments, a vent tube tor said lower compartment passing upward to said upper oonniartment, a check valve tor closing said vent tube against pressure in said lower compartment, a nd a passage from said upper compartment to said check valve tor opening the same by suction in said upper compartment.

4. A vacuum tank comprising upper and lower compartments, suction operated means :for filling said upper compartment, a check valve between said uppe and lower come partments permitting downward discharge of liquid, an atmospheric vent passage for said lower compartment, a passage between said lower and upper compartments, andv a common check valve controlling` said passages operated by suction in the upper compartment to close the passage between said compartments and automatically closing said vent passage and opening the passage between compartments when relieved ot such suction.

5. A vacuum tank comprising` upper' and lower compartments, suction operated means tor filling the upper compartment, a check valve controlled passage permitting` discharge from said upper to said lower compartments, a second passage between said upper and lower compartments, an atmospheric vent passage for said lower compartment. and a common check valve for alternatively closing the second passage, an atmospheric vent passage operated respec tively by suction in the upper compartment and by gravity.

6. In a vacuum tank, the combination with a casing having a partition therein dividing the same into an upper and a lower compartment, a suctionopeiated means for lilling the upper compartment, a downwardly opening check valve controlling the passage from said upper to said lower compartment, an atmospheric vent tube extending through said upper compartment into said lower compartment and returndient, a fitting in said return-bent portion of said tube eX- tending through said partition and provided with a lateral port communicating with said lower compartment, and a check valve in said fitting seating by gravity to close connection between said lateral port and atmospheric vent tube and lifted by suction in the upper compartment to open said vent tube and to close comnnilnication between said upper and lower compartments.

In testimony whereof I ariX my signature.

WILFRED O. CHASE. 

